The influence of rurality on melanoma diagnosis in Indiana: A retrospective cohort study

Abstract Background Research from across the United States has shown that rurality is associated with worse melanoma outcomes. In Indiana, nearly a quarter of all residents live in rural counties and an estimated 2180 cases of melanoma will be diagnosed in 2023. Aims This study examines how geographical location affects the stage of melanoma diagnosis in Indiana, aiming to identify and address rural health disparities to ultimately ensure equitable care. Methods and Results Demographics and disease characteristics of patients diagnosed with melanoma at Indiana University Health from January 2017 to September 2022 were compared using Students t‐tests, Wilcoxon tests, chi‐squared or Fisher's exact tests. Patients from rural areas presented with more pathological stage T3 melanomas (15.0% vs. 3.5%, p < 0.001) in contrast to their urban counterparts. Additionally, rural patients presented with fewer clinical stage I melanomas (80.8% vs. 89.3%) and more clinical stage II melanomas (19.2% vs. 8.1%), compared to urban patients, with no stage III (p = 0.028). Concerningly, a significantly higher percentage of the rural group (40.7%) had a personal history of BCC compared to the urban group (22.6%) (p = 0.005) and fewer rural patients (78.0%) compared to urban patients (89.4%) received surgical treatment (p = 0.016). Conclusion Patients from rural counties in Indiana have higher pathological and clinical stage melanoma at diagnosis compared to patients from urban counties. Additionally fewer rural patients receive surgical treatment and may be at higher risk of developing subsequent melanomas.

T A B L E 1 "Demographics and past medical history of rural and urban patients with melanoma in Indiana".biopsies between the two groups (Table 2).
For the treatment of melanoma, 89.4% of urban patients received surgery compared to 78.0% of rural patients (p = 0.016).However, type of surgery and reconstruction type after surgery were not significantly different between the two groups (Table 3).Additionally, little to no rural patients (0%) and urban patients (1.1%) (p > 0.999) received immunotherapy.
While immunosuppression status, personal history of melanoma and squamous cell carcinoma (SCC), and number of previous melanomas were not significantly different, a higher percentage of the rural population (40.7%) had a personal history of basal cell carcinoma (BCC) compared to the urban population (22.6%) ( p = 0.005) (Table 1).Family history of skin cancers including melanoma and nonmelanoma skin cancers (NMSC) were also not different between the two groups (Table 1 In terms of treatment, rural patients were significantly less likely to receive surgery than their urban counterparts in Indiana.This conclusion is consistent with nationwide trends that show melanoma patients from rural areas are less likely to receive recommended surgery. 9Given that surgery is still the best treatment option for localized, invasive melanoma, which represents the vast majority of tumors found in both rural and urban groups in this study, this finding is especially concerning as it pertains to melanoma-specific survival. Furthermore, we also found that a significantly higher percentage of melanoma patients from rural counties had a personal history of BCC.Based on the understanding that ultraviolet radiation (UVR) contributes to the development of both melanomas and BCCs, we believe that the rural group may have experienced more exposure to UVR prior to melanoma diagnosis and thus be at increased risk of subsequent melanoma diagnoses. 10This belief is supported by a study that found risk of melanoma to be 6.6 times higher in patients who had a prior BCC compared those who did not. 11Thus, there is significant interest in understanding the factors that result in higher stage of melanoma at diagnosis and less surgical treatment in the rural population.
While the objective of this study was not to identify factors causing disparities in melanoma diagnosis and outcomes in rural and urban populations, our data suggests that insurance status, which impacts access to care, was not the causative factor.This finding may be due to the large number of subjects in both groups of our study who were >65 years old, qualifying them for Medicare in addition to employer-sponsored insurance.Availability of TBSEs and dermatologist densities are also sometimes noted to influence melanoma outcomes.Studies have shown a decreased all-cause mortality associated with melanomas diagnosed during TBSE, likely as a result of earlier diagnosis. 12While primary care physicians sometimes conduct these exams, TBSEs are most commonly completed by dermatologists and a study from 2018 found that 88% of rural counties do not have a single dermatologist. 13It has also been found that greater dermatologist density is associated with lower melanoma mortality. 14

| CONCLUSION
Melanoma patients from rural counties in Indiana present with higher pathologic and clinical stage at diagnosis compared to their urban counter parts.Concerningly, these patients are not only less likely to receive surgical treatment but are also at higher risk of developing subsequent melanomas.Our findings highlight the disparities that rural communities in Indiana face regarding melanoma diagnosis and treatment, and pave the way for future studies to identify and address the factors leading to these findings, to ultimately ensure equitable care.
Note: Values are means (standard deviations) for age and frequencies (percentages) for categorical variables, with p-values from Student's t-tests and chisquare tests (Fischer's Exact where necessary), respectively.Other values are medians (IQRs) for continuous variables, with p-values from Wilcoxon tests.Due to missing data, counts from some variables do not add up to the total.
8,7 similar percentage of rural and urban patients did not have a regular dermatologist, 38.2% and 47.8%, respectively (p = 0.361), or a prior total body skin exam (TBSE), 38.2% and 42.7%, respectively ( p = 0.839).nosiscompared to patients from urban counties.This observation is consistent with previous investigations that have found rural patients to be diagnosed with late-stage melanoma more often that urban patients.6,7Concerningly,otherstudieshave found higher stage melanoma at diagnosis to be associated with poorer prognosis and higher mortality.8TA B L E 1 (Continued) Rural (n = 59) Urban (n = 284)